3D image display optical member and 3D image display device

ABSTRACT

A polarizing-axis control plate includes first and second polarization areas and a polarizing-axis control plate area shading part arranged at a boundary between these polarization areas and arranged in a position corresponding to an image generating area shading part to shade all or part of right-eye and left-eye image lights. When these image lights enter the first and second polarization areas respectively, the polarizing-axis control plate emits these image lights in the form of linearly-polarized lights whose polarizing axes intersect with each other at right angles or circularly-polarized lights whose polarizing axes are rotated in opposite directions. The image generating area shading part is arranged at a boundary between first and second modulated-light generating areas to shade incident light. The polarizing-axis control plate area shading part is formed to contain a plurality of straight lines each having a width narrower than a linewidth of the image generating area shading part.

This is a National Phase Application filed under 35 U.S.C. §371 as anational stage of International Application No. PCT/JP2011/058556, filedApr. 4, 2011, claiming the benefit from Japanese Patent Application No.P2010-087545, filed Apr. 6, 2010, the entire content of each of which ishereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a 3D image display optical member and a3D image display device.

BACKGROUND ARTS

For a device that allows an observer to recognize a stereoscopic image,there is known a 3D image display device including an image generatingunit for displaying an image for left eye and an image for right eye ondifferent areas and a polarizing-axis control plate that emitslinearly-polarized lights whose polarizing axes of polarized lightsincident on two different areas intersect with each other at rightangles or circularly-polarized lights whose polarizing axes are rotatedin opposite directions (see Patent Documents 1 to 5).

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Patent Publication Laid-open No. H10-232365

Patent Document 2: Japanese Patent Publication Laid-open No. 2004-264338

Patent Document 3: Japanese Patent Publication Laid-open No. H09-90431

Patent Document 4: Japanese Patent Publication Laid-open No. 2008-304909

Patent Document 5: Japanese Patent Publication Laid-open No. 2002-185983

SUMMARY OF THE INVENTION Problems to be Solved

However, moiré was sometimes generated in case of adopting thetechniques described in Patent Documents 1 to 5. The “moiré” is alsocalled “interference fringes” and means a striped pattern that isvisually produced under condition of superimposing multiple repetitiveregular patterns, due to shifts in cycle among these patterns.

In common with Patent Documents 4 and 5, for instance, a 3D imagedisplay device includes: an image generating unit having an area forgenerating an image for right eye, an area for generating an image forleft eye, pixels with red color filters, pixels with green colorfilters, pixels with blue color filters and image generating areashading parts provided with black matrixes as lattice-like blackpatterns among respective color filter areas to prevent color mixingamong adjacent red, green and blue pixels and also shade light from aback light thereby improving contrast of an image; and a polarizing-axiscontrol plate having first polarization areas for transmitting the imagefor right eye, second polarization areas for transmitting the image forleft eye after rotating it at a right angle to the polarizing axis andpolarizing-axis control plate area shading parts for reducing theoccurrence of crosstalk. In this device, as the pitches of the imagegenerating area shading parts and the polarizing-axis control plate areashading parts are close to each other, moire is generated with ease. Ingeneral, if two repetitive regular patterns are parallel to each other,then the interval (cycle) “d” of moiré on generation is represented byan expression of “d=p²/δp” on condition of representing the interval(cycle) of a first pattern by “p” and the interval (cycle) of a secondpattern by “p+δp” (on the relationship of 0<δp<p).

Between the image generating area shading parts and the polarizing-axiscontrol plate area shading parts, a glass substrate is arranged toretain the polarizing-axis control plate. These shading parts areseparated from each other at a constant distance by this glasssubstrate. Therefore, from an observer in front of the display, theimage generating area shading parts and the polarizing-axis controlplate area shading parts appear to overlap each other and do not appearto be separated from each other. Therefore, no moire is produced.However, if the observer observes a device's area far from the frontarea, the image generating area shading parts and the polarizing-axiscontrol plate area shading parts appear as if they were separated fromeach other. That is, moire is observed since a shift is produced betweenthe pitches in appearance.

Under the above-mentioned problem, an object of the present invention isto provide a 3D image display optical member and a 3D image displaydevice both of which can reduce the occurrence of moiré.

Solutions to the Problems

In order to attain the above-mentioned object, the first feature of a 3Dimage display optical member of the present invention resides in that itcomprises: an image generating unit having a first modulated-lightgenerating area to optically modulate linearly-polarized light having afirst polarizing axis with a predetermined angle based on a first imagesignal thereby generating first modulation-polarization light foremission and a second modulated-light generating area to opticallymodulate the linearly-polarized light having the first polarizing axisbased on a second image signal thereby generating secondmodulation-polarization light for emission; a polarizing plateconfigured to transmit and emit, of the first modulation-polarizationlight and the second modulation-polarization light emitted from theimage generating unit, the first modulation-polarization light and thesecond modulation-polarization light as linearly-polarized light havinga second polarizing axis different from the first polarizing axis; and apolarizing-axis control plate having a first polarization area arrangedcorresponding to the position of the first modulated-light generatingarea in the image generating unit to polarize a polarizing axis of thefirst modulation-polarization light, which has been emitted from thepolarizing plate and entered the first polarization area, to a thirdpolarizing axis thereby generating a third modulation-polarization lightfor emission, a second polarization area arranged corresponding to theposition of the second modulated-light generating area in the imagegenerating unit to polarize a polarizing axis of the secondmodulation-polarization light, which has been emitted from thepolarizing plate and entered the second polarization area, to a fourthpolarizing axis thereby generating a fourth modulation-polarizationlight for emission, and a shading part arranged at a boundary betweenthe first polarization area and the second polarization area to shadeincident light, wherein the image generating unit has an imagegenerating area shading part arranged at a boundary between the firstmodulated-light generating area and the second modulated-lightgenerating area to shade incident light, and the shading part is formedso as to contain a plurality of straight lines each having a widthsmaller than a linewidth of the image generating area shading part.

In order to attain the above-mentioned object, the second feature of a3D image display optical member of the present invention resides in thatit comprises: an image generating unit having first modulated-lightgenerating areas to optically modulate linearly-polarized light having afirst polarizing axis with a predetermined angle based on a first imagesignal thereby generating first modulation-polarization light foremission and second modulated-light generating areas to opticallymodulate the linearly-polarized light having the first polarizing axisbased on a second image signal thereby generating secondmodulation-polarization light for emission; a polarizing plateconfigured to transmit and emit, of the first modulation-polarizationlight and the second modulation-polarization light emitted from theimage generating unit, the first modulation-polarization light and thesecond modulation-polarization light as linearly-polarized light havinga second polarizing axis different from the first polarizing axis; and apolarizing-axis control plate having first polarization areas arrangedcorresponding to the positions of the first modulated-light generatingareas in the image generating unit to polarize a polarizing axis of thefirst modulation-polarization light, which has been emitted from thepolarizing plate and entered the first polarization areas, to a thirdpolarizing axis thereby generating a third modulation-polarization lightfor emission, second polarization areas arranged corresponding to theposition of the second modulated-light generating area in the imagegenerating unit to polarize a polarizing axis of the secondmodulation-polarization light, which has been emitted from thepolarizing plate and entered the second polarization areas, to a fourthpolarizing axis thereby generating a fourth modulation-polarizationlight for emission, and shading parts each arranged at a boundarybetween the first polarization area and the second polarization area toshade incident light, wherein the image generating unit has imagegenerating area shading parts each arranged at a boundary between thefirst modulated-light generating area and the second modulated-lightgenerating area to shade incident light and interpixel shading partseach arranged at a boundary between pixels provided in each of the firstmodulated-light generating areas and the second modulated-lightgenerating areas to shade incident light, the shading part is formed soas to contain at least one straight line having a width smaller than aninterval between the adjoining image generating area shading parts or aninterval between the adjoining interpixel shading parts and a pluralityof circles arranged on the side of the boundary along the straight line,the circles each having a diameter smaller than either the intervalbetween the adjoining image generating area shading parts or theinterval between the adjoining interpixel shading parts.

In order to attain the above-mentioned object, the third feature of a 3Dimage display optical member of the present invention resides in that itcomprises an image generating unit having first modulated-lightgenerating areas to optically modulate linearly-polarized light having afirst polarizing axis with a predetermined angle based on a first imagesignal thereby generating first modulation-polarization light foremission and second modulated-light generating areas to opticallymodulate the linearly-polarized light having the first polarizing axisbased on a second image signal thereby generating secondmodulation-polarization light for emission; a polarizing plateconfigured to transmit and emit, of the first modulation-polarizationlight and the second modulation-polarization light emitted from theimage generating unit, the first modulation-polarization light and thesecond modulation-polarization light as linearly-polarized light havinga second polarizing axis different from the first polarizing axis; and apolarizing-axis control plate having first polarization areas arrangedcorresponding to the positions of the first modulated-light generatingareas in the image generating unit to polarize a polarizing axis of thefirst modulation-polarization light, which has been emitted from thepolarizing plate and entered the first polarization areas, to a thirdpolarizing axis thereby generating a third modulation-polarization lightfor emission, second polarization areas arranged corresponding to theposition of the second modulated-light generating area in the imagegenerating unit to polarize a polarizing axis of the secondmodulation-polarization light, which has been emitted from thepolarizing plate and entered the second polarization areas, to a fourthpolarizing axis thereby generating a fourth modulation-polarizationlight for emission, and shading parts each arranged at a boundarybetween the first polarization area and the second polarization area toshade incident light, wherein the image generating unit has imagegenerating area shading parts each arranged at a boundary between thefirst modulated-light generating area and the second modulated-lightgenerating area to shade incident light and interpixel shading partseach arranged at a boundary between pixels provided in each of the firstmodulated-light generating areas and the second modulated-lightgenerating areas to shade incident light, the shading part is formed soas to contain a plurality of circles each having a diameter smaller thanan interval between the adjoining image generating area shading parts oran interval between the adjoining interpixel shading parts.

In order to attain the above-mentioned object, the fourth feature of a3D image display optical member of the present invention resides in thatit comprises: an image generating unit having first modulated-lightgenerating areas to optically modulate linearly-polarized light having afirst polarizing axis with a predetermined angle based on a first imagesignal thereby generating first modulation-polarization light foremission and second modulated-light generating areas to opticallymodulate the linearly-polarized light having the first polarizing axisbased on a second image signal thereby generating secondmodulation-polarization light for emission; a polarizing plateconfigured to transmit and emit, of the first modulation-polarizationlight and the second modulation-polarization light emitted from theimage generating unit, the first modulation-polarization light and thesecond modulation-polarization light as linearly-polarized light havinga second polarizing axis different from the first polarizing axis; and apolarizing-axis control plate having first polarization areas arrangedcorresponding to the positions of the first modulated-light generatingareas in the image generating unit to polarize a polarizing axis of thefirst modulation-polarization light, which has been emitted from thepolarizing plate and entered the first polarization areas, to a thirdpolarizing axis thereby generating a third modulation-polarization lightfor emission, second polarization areas arranged corresponding to thepositions of the second modulated-light generating areas in the imagegenerating unit to polarize a polarizing axis of the secondmodulation-polarization light, which has been emitted from thepolarizing plate and entered the second polarization areas, to a fourthpolarizing axis thereby generating a fourth modulation-polarizationlight for emission, and shading parts each arranged at a boundarybetween the first polarization area and the second polarization area toshade incident light, wherein the image generating unit has imagegenerating area shading parts each arranged at a boundary between thefirst modulated-light generating area and the second modulated-lightgenerating area to shade incident light and interpixel shading partseach arranged at a boundary between pixels provided in each of the firstmodulated-light generating areas and the second modulated-lightgenerating areas to shade incident light, the shading part includes aplurality of rectangles arranged along the boundary between the firstpolarization area and the second polarization area and also arranged soas to be shifted from rectangles in the shading part provided at theadjoining boundary, in the arranging direction of the rectangles by only⅓ to ½ of a horizontal pitch at which the rectangles provided at theadjoining boundary are arranged.

In order to attain the above-mentioned object, the first feature of a 3Dimage display device of the present invention resides in that itcomprises: a light source; a linearly-polarized light generating unitconfigured to transmit, of light emitted from the light source, firstlinearly-polarized light having the first polarizing axis; and the 3Dimage display optical member of any of the first to fourth features,wherein an image generated by the third modulation-polarization lightemitted from the first polarization area of the polarizing-axis controlplate is established as a right-eye image, while an image generated bythe fourth modulation-polarization light emitted from the secondpolarization area is established as a left-eye image.

Effects of the Invention

According to the 3D image display optical member and the 3D imagedisplay device of the present invention, it is possible to reduce thevisibility of moire.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG.1 is an exploded perspective view of a 3D image display device inaccordance with an embodiment 1 of the present invention.

FIG.2 is a perspective view showing another form of a polarizing-axiscontrol plate of the 3D image display device of the embodiment 1 of thepresent invention.

FIG.3 is a schematic view showing the usage state of the 3D imagedisplay device of the embodiment 1 of the present invention.

FIG.4 is an enlarged plan view of a part of an image generating unitthat the 3D image display device of the embodiment 1 of the presentinvention includes.

FIG.5 is a sectional view illustrating an example of respective sectionsof the image generating unit and the polarizing-axis control plate undercondition that neither an image generating area shading part nor apolarizing-axis control plate shading part is formed.

FIG.6 is a sectional view illustrating an example of respective sectionsof the image generating unit and the polarizing-axis control plate thatthe 3D image display device of the embodiment 1 of the present inventionincludes.

FIG.7 is an enlarged view of the image generating unit used in anexperiment for investigating a change of moiré in the 3D image displaydevice of the embodiment 1 of the present invention.

FIGS. 8( a) to 8(e) are views showing comparative and experimentalexamples of the linear patterns of polarizing-axis control plate shadingparts in the 3D image display device of the embodiment 1 of the presentinvention.

FIGS. 9( a) to 9(e) are views showing comparative and experimentalexamples of the linear patterns of the polarizing-axis control plateshading parts in the 3D image display device of the embodiment 1 of thepresent invention.

FIG. 10 is a diagram showing the results of evaluating moiré and lighttransmission rates about the comparative and experimental examples shownin FIGS. 8 and 9 in the 3D image display device of the embodiment 1 ofthe present invention.

FIGS. 11( a) to 11(e) are views showing experimental examples of linearpatterns of the polarizing-axis control plate shading parts in the 3Dimage display device of the embodiment 1 of the present invention.

FIG. 12 is a diagram showing the results of evaluating moiré and lighttransmission rates about the comparative example of FIG. 8( a) and theexperimental example of FIG. 11 in the 3D image display device of theembodiment 1 of the present invention.

FIGS. 13( a) to 13(c) are views showing experimental examples of thelinear patterns of the polarizing-axis control plate shading parts inthe 3D image display device of the embodiment 1 of the presentinvention.

FIG. 14 is a diagram showing the results of evaluating moiré and lighttransmission rates about the comparative example of FIG. 8( a) and theexperimental example of FIG. 13 in the 3D image display device of theembodiment 1 of the present invention.

FIGS. 15( a) to 15(e) are views showing experimental examples of thelinear patterns of the polarizing-axis control plate shading parts inthe 3D image display device of the embodiment 1 of the presentinvention.

FIG. 16 is a diagram showing the results of evaluating moiré and lighttransmission rates about the comparative example of FIG. 8( a) and theexperimental example of FIG. 16 in the 3D image display device of theembodiment 1 of the present invention.

FIG. 17 is a diagram showing the result of a crosstalk ratio withrespect to each view angle about a comparative example of FIG. 8( a), anexperimental example 1-1 of FIG. 8( b) and an experimental example 5-2of FIG. 13( a) in the 3D image display device of the embodiment 1 of thepresent invention.

FIG. 18 is a perspective view showing another embodiment of thepolarizing-axis control plate in the 3D image display device of theembodiment 1 of the present invention.

FIG. 19 is a perspective view showing the other embodiment of thepolarizing-axis control plate in the 3D image display device of theembodiment 1 of the present invention.

FIG. 20 is an enlarged plan view of a part of an image generating unitof another embodiment that the 3D image display device of the embodiment1 of the present invention includes.

FIG. 21 is an exploded perspective view of a 3D image display device inaccordance with an embodiment 2 of the present invention.

FIG. 22 is a constitutional view showing the constitution of a 3D imagedisplay device in accordance with an embodiment 3 of the presentinvention.

FIG. 23(A) is an enlarged view of dots of FIG. 8( b) showing its designstatus, while FIG. 23(B) is an enlarged view of dots formed under thecondition of FIG. 23(A) actually.

EMBODIMENTS OF THE INVENTION

Several embodiments of the present invention will be described belowwith reference to drawings.

<Embodiment 1>

FIG. 1 is an exploded perspective view of a 3D image display device 100of the embodiment 1.

The 3D image display device 100 includes a light source 120, an imagedisplay unit 130 and a polarizing-axis control plate (3D image displayoptical member) 180, in order illustrated in FIG. 1. They areaccommodated in a not-shown casing. Again, the image display unit 130includes a polarizing plate (linearly-polarized light generating unit)150, an image generating unit 160 and a polarizing plate 170. Here, itis assumed that an observer observes a stereoscopic image displayed onthe 3D image display device 100 from a direction of arrow X1 of FIG. 1(from the right side of the polarizing-axis control plate 180).

The light source 120, which is arranged in the innermost side of the 3Dimage display device 100 when seen from the observer, is a reflectiontype polarizing plate provided to effectively utilize white unpolarizedlight or light from the light source transmits light under condition ofusing the 3D image display device 100 (referred to as “usage state ofthe 3D image display device 100” below). This polarizing plate transmitslight identical to a direction for the polarizing plate 150 and alsoreflects the other light components for return. Then, the so-reflectedlight components are reflected in a backlight unit for emission, furtherpolarized by the reflection type polarizing plate and emitted toward asurface of the polarizing plate 150. Although a surface illuminant isadopted as the light source 120 in the embodiment 1, it may be replacedwith a combination of a point light source with a condenser lensinstead. By way of example, a Fresnel lens sheet is available as thecondenser lens.

The polarizing plate 150 is located on one side of the image generatingunit 160, facing the light source 120. The polarizing plate 150 has atransmission axis and an absorption axis intersecting with thetransmission axis at right angles. When unpolarized light emitted fromthe light source 120 enters, the polarizing plate transmits, of theunpolarized light, a light component having a polarizing axis parallelto the transmission axis and cuts off a light component having apolarizing axis parallel to the absorption axis. Here, the polarizingaxis means a vibration direction of electrical field in the light. Thetransmission axis of the polarizing plate 150 is 45-degree inclined inthe upper right or lower left to the horizontal direction on conditionthat an observer sees the 3D image display device 100, as shown witharrow Y1 of FIG. 1. Accordingly, the light emitted from the polarizingplate 150 becomes linearly-polarized light having an inclination of45-degree to the horizontal direction.

The image generating unit 160 includes pixels corresponding to redlight, green light and blue light, respectively. Further, the imagegenerating unit 160 has right-eye image generating areas 162 eachcomposed of a plurality of pixels and left-eye image generating areas164 each composed of a plurality of different pixels from those of theright-eye image generating areas 162. The image generating unit 160,such as liquid crystal display elements, serves to optically modulateincident light on the basis of image signals inputted from the outside.The right-eye image generating areas 162 and the left-eye imagegenerating areas 164 are areas obtained by segmentalizing the imagegenerating unit 160 in the horizontal direction, as shown in FIG. 1.Multiple right-eye image generating areas 162 and multiple left-eyeimage generating areas 164 are arranged in the vertical direction,alternately.

In the usage state of the 3D image display device, an image for righteye and an image for left eye are generated in the right-eye imagegenerating areas 162 and the left-eye image generating areas 164 of theimage generating unit 160 respectively by a right-eye image signal and aleft-eye image signal supplied from the outside. When part of lightpenetrating through the polarizing plate 150 enters the right-eye imagegenerating areas 162 on condition that the right-eye image is beinggenerated in the right-eye image generating areas 162, the incidentlight is optically modulated on the basis of the right-eye image signal,so that image light for a right-eye image (referred to as “right-eyeimage light” for short, below) is emitted from the right-eye imagegenerating areas 162. In addition, when part of light penetratingthrough the polarizing plate 150 enters the left-eye image generatingareas 164 on condition that the left-eye image is being generated in theleft-eye image generating areas 164, the incident light is opticallymodulated on the basis of the left-eye image signals, so that imagelight for a left-eye image (referred to as “left-eye image light” forshort, below) is emitted from the left-eye image generating areas 164.Regarding the right-eye image light emitted from the right-eye imagegenerating areas 162 and the left-eye image light emitted from theleft-eye image generating areas 164, respective polarizing axes arerotated in image light's areas optically-modulated based on the imagesignals. In addition, at the boundary parts of respective pixels of theimage generating unit 160, shading parts called “black matrixes” arearranged to reduce color mixture among red light, green light and bluelight. In addition, in the black matrix, image generating area shadingparts 163 as band-like black stripes are formed at respective boundariesbetween the right-eye image generating areas 162 and the left-eye imagegenerating areas 164, horizontally.

The polarizing plate 170 is located on one side of the image generatingunit 160, facing the observer. When the right-eye image lightpenetrating through the above-mentioned right-eye image generating areas162 and the left-eye image light penetrating through left-eye imagegenerating areas 164 enter, this polarizing plate 170 transmits apolarization component of these light components, which has itspolarizing axis parallel to the transmission axis, and also cuts off apolarization component having its pluralizing axis parallel to theabsorption axis. Here, the transmission axis of the polarizing plate 170is 45-degree inclined in the upper left and lower right directions tothe horizontal direction on condition that the observer sees the 3Dimage display device 100, as shown with arrow Y2 of FIG. 1. Accordingly,the light emitted from the polarizing plate 170 becomeslinearly-polarized light intersecting with the light emitted from thepolarizing plate 150 at right angles and also having an inclination of45-degree to the horizontal direction. In addition, by making thedirection of the transmission axis of the polarizing plate 170 generallyidentical to the directions of the polarizing axes of the right-eyeimage light and the left-eye image light emitted from the imagegenerating unit 160, it is possible to improve the brightness of the 3Dimage display device 100.

The polarizing-axis control plate 180 includes a substrate 184, firstpolarization areas 181 and second polarization areas 182 both formed onthe substrate 184. In this polarizing-axis control plate 180, thepositions and sizes of the first polarization areas 181 and the secondpolarization areas 182 correspond to the positions and sizes of theright-eye image generating areas 162 and the left-eye image generatingareas 164 of the image generation part 160 respectively, as shown inFIG. 1. Therefore, in the usage state of the 3D image display device100, the right-eye image light penetrating through the right-eye imagegenerating areas 162 enters the first polarization areas 181, while theleft-eye image light penetrating through the left-eye image generatingareas 164 enters the second polarization areas 182.

The first polarization area 181 rotates the polarizing axis of theincident right-eye image light 90 degrees to a direction perpendicularto the polarizing axis of the left-eye image light incident on thesecond polarization area 182. On the other hand, the second polarizationarea 182 transmits the incident left-eye image light as it is withoutrotating its polarizing axis. Therefore, the polarizing axis of theright-eye image light penetrating through the first polarization area181 and the polarizing axis of the left-eye image light penetratingthrough the second polarization area 182 directionally intersect witheach other at right angles, as shown with arrows Y3, Y4 of FIG. 1. Notethat, in FIG. 1, the arrows Y3, Y4 shown in the first polarization areas181 and the second polarization areas 182 of the polarizing-axis controlplate 180 represent respective directions of the polarizing axes of thepolarized light passing through respective polarization areas.

For the substrate 184 of the polarizing-axis control plate 180, there isused a plate member made of e.g. low-birefringence transparent glass,low-birefringence resin, etc. or a film member having low birefringenceso as not to change the direction of a polarizing axis of incident imagelight. For the first polarization area 181, there is used, for example,a half wavelength plate made from birefringent material, having a natureof rotating the direction of a polarizing axis of incident right-eyeimage light by 90-degrees. Further, for the second polarization area182, there is adopted means of direct transmitting the light withoutanything on the substrate 184, for the purpose of allowing the incidentleft-eye image light to be transmitted as it is without changing thedirection of its polarizing axis. Alternatively, there is used a membermade of low-birefringence glass or resin or a polarizing plate having asimilar polarization to the polarizing plate 170. As a result, thepolarizing axis of the right-eye image light and the polarizing axis ofthe left-eye image light both emitted from the polarizing-axis controlplate 180 directionally intersect with each other at right angles.

Further, the polarizing-axis control plate 180 is provided, on itssurface facing the image display unit 130, with strip-shapedpolarizing-axis control plate area shading parts 183 on the side of theplate 180 facing the image display unit 130, at each boundary betweenthe first polarization areas 181 and the second polarization areas 182.By providing the polarizing-axis control plate area shading part 183like this, it is possible to absorb and interrupt, of the left-eye imagelight to be entered into the second polarization area 182 adjacent tothe first polarization area 181 of the polarizing-axis control plate180, image light part entering the first polarization area 181 over theabove boundary. Similarly, of the right-eye image light to be enteredinto the first polarization area 181 adjacent to the second polarizationarea 182 of the polarizing-axis control plate 180, it is possible toabsorb and interrupt image light part entering the second polarizationarea 182 over the above boundary. Therefore, crosstalk becomes unlikelyto be produced in the right-eye image light and the left-eye image lightemitted from the 3D image display device 100. The details of thiscrosstalk will be described later.

In another form of the polarizing-axis control plate 180, as shown inFIG. 2, there may be adopted a structure including the substrate 184 andthe second polarization areas 182 formed on the substrate 184.

In addition, the above 3D image display device 100 may include adiffusion plate that is arranged on one side of the polarizing-axiscontrol plate 180 facing the observer (on the right side of thepolarizing-axis control plate 180 in FIG. 1) to diffuse the right-eyeimage light and the left-eye image light penetrating through the firstpolarization areas 181 and the second polarization areas 182 to at leastone, horizontal direction or vertical direction. For such a diffusionplate, there is used, for instance, either a lenticular lens sheethaving a plurality of vault-shaped convex lenses (cylindrical lenses)stretched in the horizontal or vertical direction or a lens array sheethaving a plurality of convex lenses arranged in a plane.

FIG. 3 is a schematic view showing the usage state of the 3D imagedisplay device 100.

When viewing a stereoscopic image by the 3D image display device 100, anobserver 500 views the right-eye image light and the left-eye imagelight projected from the 3D image display device 100 while putting onpolarizing glasses 200. When the observer 500 puts on the polarizingglasses 200, a right-eye image transmission part 232 of the polarizingglasses 200 is located in a position corresponding to a right eye 512 ofthe observer 500, while a left-eye image transmission part 234 islocated in a position corresponding to a left eye 514. The right-eyeimage transmission part 232 and the left-eye image transmission part 234are polarizing lenses whose transmission axes are different in directionfrom each other and which are fixed on a frame of the polarizing glasses200.

The right-eye image transmission part 232 is a polarizing plate whosetransmission axis has the same orientation as the right-eye image lightpenetrating through the first polarization areas 181 and whoseabsorption axis has an orientation perpendicular to the abovetransmission axis. The left-eye image transmission part 234 is apolarizing plate whose transmission axis has the same orientation as theleft-eye image light penetrating through the second polarization areas182 and whose absorption axis has an orientation perpendicular to theabove transmission axis. For the right-eye image transmission part 232and left-eye image transmission part 234, there are used, for instance,polarizing glasses on which a polarization film obtained byuniaxial-drawing a film impregnated with dichroic dye is applied.

When viewing the stereoscopic image through the 3D image display device100, the observer 500 observes the 3D image display device 100 whileputting on the polarizing glasses 200 within the emitting range of theright-eye image light penetrating through the first polarization areas181 and the left-eye image light penetrating through the secondpolarization areas 182. As a result, the observer can observe only aright-eye image contained in the right-eye image light left by anobserver's right eye 512 and observe only a left-eye image contained inthe left-eye image light left by an observer's left eye 514. Thus, theobserver 500 can recognize the right-eye image and left-eye image in theform of a stereoscopic image.

FIG. 4 is an enlarged plan view of a part of the image generating unit160.

In the image generating unit 160, as shown in FIG. 4, the right-eyeimage generating area 162 and the left-eye image generating area 164 arerespectively divided into a plurality of tiny cells in the horizontaldirection. Each of these cells constitutes a pixel 360 as a minimumunit, to be optically modulated by an image signal applied from theoutside. Each pixel 360 is provided with red, green and blue colorfilters indicative of three primary colors, providing a red indicatingpixel 361, a green indicating pixel 362 and a blue indicating pixel 363,respectively.

Note that, in the right-eye image generating area 162 and the left-eyeimage generating area 164 of the image generating unit 160, for example,the red display pixel 361, the green display pixel 362 and the bluedisplay pixel 363 are arranged in this order repeatedly, in thehorizontal direction.

Moreover, as for the provision of black matrixes to prevent colormixture between the adjacent areas segmentalized by the color filters,the image generating area shading part 163 in the form of a black stripeas part of the black matrixes is formed at the boundary part ofrespective pixels including each boundary between the right-eye imagegenerating area 162 and the left-eye image generating area 164 of theimage generating unit 160.

The crosstalk will be described here.

FIG. 5 is a sectional view illustrating one example of respectivesections of the image generating unit 160 and the polarizing-axiscontrol plate 180 in case that neither the image generating area shadingpart 163 nor the polarizing-axis control plate area shading part 183 ispresent.

In view from the observer 500, as shown in FIG. 5, the polarizing-axiscontrol plate 180 is arranged in front of the image generating unit 160so that the first polarization areas 181 are located ahead of theright-eye image generating areas 162 respectively, while the secondpolarization areas 182 are located ahead of the left-eye imagegenerating areas 164 respectively.

The right-eye image light is emitted from the right-eye image generatingarea 162. Then, the emitted right-eye image light enters the firstpolarization area 181 where the vibrating direction of polarization isrotated 90-degrees and thereafter, the right-eye image light reaches theobserver 500. On the other hand, the left-eye image light is emittedfrom the left-eye image generating area 164. Then, the emitted left-eyeimage light penetrates through the second polarization area 182 andreaches the observer 500.

Thus, in order to display a right-eye image and a left-eye image on the3D image display device 100, it is required that the right-eye imagelight emitted from the right-eye image generating areas 162 enters thefirst polarization area 181, while the left-eye image light emitted fromthe left-eye image generating areas 164 enters the second polarizationarea 182.

For example, if the left-eye image light emitted from the left-eye imagegenerating area 164 enters into the first polarization area 181, thenthe incident light turns to an image captured by the right-eye imagetransmission part 232 of the observer 500 since the vibrating directionof polarization is rotated 90-degrees. Of course, as this image isdifferent from the original right-eye image, there is a possibility ofcausing a problem that the image captured by the observer 500 blurs andthe stereoscopic effect becomes unclear, etc.

In the conventional art, however, it is very difficult to arrange theimage generating unit 160 and the polarizing-axis control plate 180 withhigh accuracy so that the right-eye image light and the left-eye imagelight emitted from the image generating unit 160 can be all introducedinto the first polarization areas 181 and the second polarization areas182, respectively.

It is desirable that the right-eye image generating areas 162 and theleft-eye image generating areas 164 are arranged densely (reduced inwidth) in order to obtain a clear image. In this case, however, it isvery difficult to precisely position the first polarization areas 181and the second polarization areas 182 so as to correspond to theright-eye image generating areas 162 and the left-eye image generatingareas 164 respectively, ahead of the image generating unit 160 where theright-eye image generating areas 162 and the left-eye image generatingareas 164 are arranged densely. Specifically, as the general firstpolarization areas 181 and the general second polarization areas 182 aremicroscopically linear-shaped with each width of approx. 200 μm, it isvery difficult to precisely arrange them at the positioning level of“ten-odd μm”,allowing a displacement of less than 5%.

Moreover, as both the right-eye image light emitted from the right-eyeimage generating areas 162 and the left-eye image light emitted from theleft-eye image generating areas 164 are not parallel lights completely,there is a case that, for example, part of left-eye image light emittedfrom the vicinity of an upper end of the left-eye image generating area164 shown in FIG. 5 enters the first polarization area 181 (arrow 10shown in FIG. 5).

Furthermore, there is also a possibility that the left-eye image lightemitted from the left-eye image generating area 164 once enters thesecond polarization area 182 and subsequently enters the firstpolarization area 181 (arrow 11 shown in FIG. 5). This phenomenon isgenerally called “crosstalk ”. In this case, the vibrating direction ofpolarization of the left-eye image light shown with arrow 11 will berotated within the range of 0 to 90-degrees. For instance, if it isrotated 45-degrees, the left-eye image light will pass through theright-eye image transmission part 232 and the left-eye imagetransmission part 234, each with a light intensity of 50%. Also in thisregard, there arises a problem that the image captured by the observer500 blurs and the stereoscopic effect becomes unclear, etc.

Therefore, the 3D image display device 100 in accordance with theembodiment 1 includes the polarizing-axis control plate 180 equippedwith the polarizing-axis control plate area shading parts 183.

FIG. 6 is a sectional view illustrating one example of respectivesections of the image generating unit 160 and the polarizing-axiscontrol plate 180 included in the 3D image display device 100 of theembodiment 1.

As shown in FIG. 6, in the image generating unit 160, the right-eyeimage generating areas 162 and the left-eye image generating areas 164are juxtaposed to each other alternately. Further, the image generatingarea shading part 163 as a black stripe is formed at the boundarybetween the right-eye image generating area 162 and the left-eye imagegenerating area 164 of the image generating unit 160.

Moreover, in the polarizing-axis control plate 180, the stripe-shapedpolarizing-axis control plate area shading part 183 for reducingcrosstalk is formed at the boundary between the second polarization area182 and the first polarization area 181.

The image generating area shading parts 163 and the polarizing-axiscontrol plate area shading parts 183 are formed by means of printingtechniques, photolithographic method, etc. using ultraviolet curingresin or thermosetting resin with the addition of black dye. Normally,the polarizing-axis control plate area shading parts 183 are formed soas to be black stripes. Here, there are relief printing, lithography,intaglio printing, mimeograph printing, screen-stencil, offset printing,etc. available for the printing techniques.

Consequently, it is possible to absorb and interrupt, of the left-eyeimage light to be entered into the second polarization area 182 adjacentto the first polarization area 181, image light part entering the firstpolarization area 181 across the above boundary.

Similarly, it is possible to absorb and interrupt, of the right-eyeimage light to be entered into the first polarization area 181 adjacentto the second polarization area 182 of the polarizing-axis control plate180, image light part entering the second polarization areas 182 acrossthe above boundary. Therefore, crosstalk becomes unlikely to be producedin the right-eye image light and the left-eye image light emitted fromthe 3D image display device 100.

Therefore, when viewing the stereoscopic image through the 3D imagedisplay device 100, the observer 500 observes the 3D image displaydevice 100 while putting on the polarizing glasses 200 within theemitting range of the right-eye image light penetrating through thefirst polarization areas 181 and the left-eye image light penetratingthrough the second polarization areas 182. As a result, the observer canobserve only a right-eye image contained in the right-eye image lightleft by an observer's right eye and observe only a left-eye imagecontained in the left-eye image light left by an observer's left eye.Thus, the observer 500 can recognize these right-eye image and left-eyeimage in the form of a stereoscopic image.

However, as the pitch of the image generating area shading parts 163approximates the pitch of the polarizing-axis control plate area shadingparts 183, moiré is easy to be produced.

In the polarizing-axis control plate area shading part 183 of thepolarizing-axis control plate 180 included in the 3D image displaydevice 100 of the embodiment 1, therefore, a single black stripe ismulti-segmentalized into a variety of linear patterns to reduce theoccurrence of moiré. Here, as the linear patterns obtained bymulti-segmentalizing the black stripe, there are straight linesmulti-segmentalized in the vertical direction and aggregation of(rectangular, circular, oblong, polygonal) dots arranged at regularintervals in the horizontal direction.

In this way, as the linear pattern of the polarizing-axis control platearea shading part 183 is multi-segmentalized, the occurrence state ofmoiré also changes depending on the resulting multi-segmentalizedprofile.

<<Fundamental Experiments for Evaluating Influence of Linear-PatternProfile on Moiré Occurrence>>

Thus, we carried out experiments for investigating the change of moiréand the change of light transmission rate by modifying the profile ofthe linear pattern, as shown below.

In the 3D image display device 100 of the embodiment 1, FIG. 7 is anenlarged view of the image generating unit 160 used for the experimentfor investigating the change of moiré and the change of lighttransmission rate. In addition, FIG. 7 shows one example of dimensionsof the image generating unit 160 included in the 3D image display device100 having a 24-inch screen.

As shown in FIG. 7, the right-eye image generating area 162 and theleft-eye image generating area 164 of the image generating unit 160 arerespectively divided into a plurality of tiny cells in the horizontaldirection, so that each of these cells provides any of the red displaypixel 361, the green display pixel 362 and the blue display pixel 363.Further, at respective boundaries among the red display pixel 361, thegreen display pixel 362, and the blue display pixel 363, interpixelshading parts 165 as the black stripes are formed to extend in thevertical direction.

As shown in FIG. 7, as respective horizontal widths of the red displaypixel 361, the green display pixel 362 and the blue display pixel 363are 0.06 (mm) each, the interval of the interpixel shading parts 165adjoining in the horizontal direction is 0.03 (mm). Moreover, sincerespective vertical widths of the red display pixel 361, the greendisplay pixel 362 and the blue display pixel 363 are 0.105 (mm) each,the interval of the interpixel shading parts 165 adjoining in thevertical direction is 0.02 (mm). In addition, the red display pixel 361,the green display pixel 362 and the blue display pixel 363 arerespectively formed with the interpixel shading parts 165 as the blackstripes extending in the oblique direction. As respective oblique widthsof the red display pixel 361, the green display pixel 362 and the bluedisplay pixel 363 is 0.06 (mm) each, the interval of the pixel shadingparts 165 adjoining in the oblique direction is 0.01 (mm).

Moreover, as shown in FIG. 7, the image generating area shading part 163formed at the boundary between the right-eye image generating area 162and the left-eye image generating area 164 of the image generating unit160 has a linewidth of 0.04 (mm).

FIGS. 8( a) to 8(e) are views showing comparative and experimentalexamples of linear pattern of the polarizing-axis control plate shadingparts 183 in the 3D image display device 100 of the embodiment 1.

FIG. 8( a) shows the polarizing-axis control plate area shading partsconstructed by the linear pattern where respective lines each having awidth of 0.135 (mm) are arranged parallel to one another in thehorizontal direction, at the pitch of 0.27 (mm), as the comparativeexample. In connection with the linear pattern where the lines eachhaving a width of 0.135 (mm) are arranged parallel to one another in thehorizontal direction at the pitch of 0.27 (mm), as the experimentalexample 1-1, FIG. 8( b) shows the polarizing-axis control plate areashading parts 183 where respective circles each having a diameter of0.05 (mm) are arranged regularly in each line, obliquely andhorizontally. Here, the horizontal pitch of circles is 0.06 (mm), whilethe vertical pitch is 0.04 (mm). In the linear pattern where lines eachhaving a width of 0.130 (mm) are arranged parallel to one another in thehorizontal direction at the pitch of 0.27 (mm), as the experimentalexample 1-2, FIG. 8( c) shows the polarizing-axis control plate areashading parts 183 where squares of 0.10 (mm) per side are arranged atregular intervals of 0.032 (mm) in each line, in the horizontaldirection. In the linear pattern where lines each having a width of0.130 (mm) are arranged parallel to one another in the horizontaldirection at the pitch of 0.27 (mm), as the experimental example 1-3,FIG. 8( d) shows the polarizing-axis control plate area shading parts183 where each line is composed of two straight lines each having awidth of 0.049 (mm), extending in the horizontal direction. The intervalbetween two straight lines is 0.032 (mm) In the linear pattern wherelines each having a width of 0.130 (mm) are arranged parallel to oneanother in the horizontal direction at the pitch of 0.27 (mm), as theexperimental example 1-4, FIG. 8( e) shows the polarizing-axis controlplate area shading parts 183 where each line is composed of three linesin total: two straight lines each having a width of 0.032 (mm) and asingle straight line having a width of 0.034 (mm) and interposed betweenthe straight lines in pairs. Among the three lines, respective intervalsbetween two adjoining straight lines are 0.016 (mm) each.

As similar to FIGS. 8( a) to 8(e), FIGS. 9( a) to 9(e) are views showingexperimental examples of linear patterns of the polarizing-axis controlplate shading parts 183 in the 3D image display device 100 of theembodiment 1.

As the experimental example 2-1, FIG. 9( a) shows the polarizing-axiscontrol plate area shading parts 183 constructed by the linear patternwhere respective lines each having a width of 0.135 (mm) are arrangedparallel to one another in the horizontal direction at the pitch of 0.27(mm), each line comprising elliptical oblique lines each having a widthof 0.035 mm arranged regularly at the pitch of 0.10 (mm) in thehorizontal direction. Here, each of the oblique lines has a projectionlength of 0.235 (mm) to the horizontal direction. As the experimentalexample 2-2, FIG. 9( b) shows the polarizing-axis control plate areashading parts 183 constructed by the linear pattern where respectivelines each having a width of 0.135 (mm) are arranged parallel to oneanother in the horizontal direction at the pitch of 0.27 (mm), each linecomprising elliptical lines each having a longitudinal length of 0.135mm arranged regularly at the pitch of 0.14 (mm) in the horizontaldirection. As the experimental example 2-3, FIG. 9( c) shows thepolarizing-axis control plate area shading parts 183 constructed by thelinear pattern where respective lines each having a width of 0.135 (mm)are arranged parallel to one another in the horizontal direction at thepitch of 0.27 (mm), each line comprising rectangular oblique lines of0.035 (mm) per side arranged regularly at the pitch of 0.13 (mm) in thehorizontal direction. Here, each of the elliptical lines has aprojection length of 0.235 (mm) to the horizontal direction. As theexperimental example 2-4, FIG. 9( d) shows the polarizing-axis controlplate area shading parts 183 constructed by the linear pattern whererespective lines each having a width of 0.135 (mm) are arranged parallelto one another in the horizontal direction at the pitch of 0.27 (mm),each line comprising respective pairs of three circles: one great circlehaving a diameter of 0.095 (mm) and two small circles each having adiameter of 0.035 (mm), the respective pairs of circles being arrangedregularly at the pitch of 0.10 (mm) so that the adjoining pairs areoppositely-arranged in the vertical direction alternately. Here, thehorizontal interval between two small circles is 0.06 (mm). As theexperimental example 2-5, FIG. 9( e) shows the polarizing-axis controlplate area shading parts 183 constructed by the linear pattern whererespective lines each having a width of 0.130 (mm) are arranged parallelto one another in the horizontal direction at the pitch of 0.27 (mm),each line comprising respective graphic symbols arranged regularly atthe pitch of 0.06 (mm) in the horizontal direction. Each graphic symbolis formed by an integration of a single line having a width of 0.05 (mm)with circles each having a diameter of 0.05 (mm) on both sides of thesingle line in the vertical direction, the single line and the circlesbeing arranged so as to partially overlap each other along the singleline. Here, in each graphic symbol, the center-to-center distancebetween two circles is 0.08 (mm).

For the 3D image display device 100 of the embodiment 1, FIG. 10 is adiagram showing the results of evaluating moire and light transmissionrates for the experimental examples shown in FIGS. 8( a) to 8(e) andFIGS. 9( a) to 9(e). Suppose that the evaluated values of moire rangeare from 0 to 5. Also suppose that, on condition of viewing moire at thefront, oblique and vertical observing positions, the smaller theevaluated value gets, the more the moire is difficult to be observed,and the larger the evaluated value gets, the more the moire becomesclear as well. It is assumed that the evaluated values of moire in frontand oblique positions are “5” in the arrangement where thepolarizing-axis control plate area shading part 183 is formed by asingle straight line at one boundary, namely, in the comparativeexample. On this assumption, we evaluated respective moire s viewed fromthe front, oblique and vertical positions in each experiment and furthercalculated a sum of evaluated values of moire on evaluation.

Moreover, the light transmission rates were obtained by measuringrespective transparent plates with the polarizing-axis control platearea shading parts 183 with the use of a total-light flux transmittancemeter (HR-100 made by Murakami Color Research Laboratory Co. Ltd.), andthe artificial judgment was performed based on the sum of evaluatedvalues of moire and the light transmission rate. On condition that thelight transmission rate exceeds 45 (%), concretely, if the sum ofevaluated values of moire is more than or equal to 0 and less than orequal to 3, the artificial judgment was represented by “⊚”. If the sumof evaluated values of moire exceeds 3 and is less than or equal to 5,the artificial judgment was represented by “◯”.If the sum of evaluatedvalues of moire exceeds 5 and less than or equal to 7, the artificialjudgment was represented by “Δ”. If the sum of evaluated values of moireexceeds 7 and less than or equal to 10, the artificial judgment wasrepresented by “x”. If the sum of evaluated values of moire exceeds 10,the artificial judgment was represented by “xx”.

As shown in FIG. 10, as the sums of evaluated values of moiré in theexperimental examples 1-1, 1-4 and 2-1 represent small values of “4”,“3.5” and “5” respectively while the sum of evaluated values of moiré inthe comparative example is “10”, it can be said that these experimentalexamples have a constant effect of reducing the occurrence of moiré. Inaddition, since the light transmission rates in the experimentalexamples 1-1, 1-4 and 2-1 represent large values of “58”, “56” and “57”respectively in comparison with the light transmission rate of “45” (%)in the comparative example, it is found that the screens are increasedin brightness in comparison with the comparative example.

Furthermore, as the sum total of evaluated values of moiré in theexperimental example 2-5 represents a remarkably small value of “3” incomparison with “10” in the comparative example and the lighttransmission rate represents a large value of “55”, it can be said thatthe experimental example 2-5 enables the screen to be increased inbrightness in comparison with the comparative example and has a greatereffect of reducing the occurrence of moiré.

In this way, according to the 3D image display device 100 of theembodiment 1, since the optical random nature is produced by changingthe linear pattern profiles of the polarizing-axis control plate areashading parts 183 to reduce an interference between the image generatingarea shading parts 163 and the interpixel shading parts 165, it ispossible to improve the light transmission rate and reduce theoccurrence of moiré.

<<Experiments for Evaluating Influence of Circle Diameter and Line Widthon Moiré Occurrence>>

Next, we carried out experiments for investigating the change of moiréand the change of light transmission rate by changing the diameters ofcircles and the widths of lines included in the polarizing-axis controlplate area shading parts 183, as shown below.

FIGS. 11( a) to 11(e) are views showing experimental examples of linearpatterns of the polarizing-axis control plate shading parts 183 in the3D image display device 100 of the embodiment 1.

As the experimental example 3-2, FIG. 11( a) shows the polarizing-axiscontrol plate area shading parts 183 constructed by the linear patternwhere respective lines each having a width of 0.160 (mm) are arrangedparallel to one another in the horizontal direction at the pitch of 0.27(mm), each line comprising respective circles each having a diameter of0.06 (mm) arranged regularly in the oblique and horizontal directions.Here, the horizontal pitch of circles is 0.08 (mm), while the verticalpitch is 0.05 (mm). As the experimental example 3-3, FIG. 11( b) showsthe polarizing-axis control plate area shading parts 183 constructed bythe linear pattern where respective lines each having a width of 0.190(mm) are arranged parallel to one another in the horizontal direction atthe pitch of 0.27 (mm), each line comprising respective circles eachhaving a diameter of 0.07 (mm) arranged regularly in the oblique andhorizontal directions. Here, the horizontal pitch of circles is 0.09(mm), while the vertical pitch is 0.06 (mm). As the experimental example4-3, FIG. 11( c) shows the polarizing-axis control plate area shadingparts 183 constructed by the linear pattern where lines having a widthof 0.130 (mm) are arranged parallel to one another in the horizontaldirection at the pitch of 0.27 (mm), each line comprising three straightlines each having a width of 0.03 (mm), extending in the horizontaldirection. Here, in these three straight lines, the intervals betweentwo lines are 0.02 (mm) respectively. As the experimental example 4-4,FIG. 11( d) shows the polarizing-axis control plate area shading parts183 constructed by the linear pattern where lines having a width of0.138 (mm) are arranged parallel to one another in the horizontaldirection at the pitch of 0.27 (mm), each line comprising five straightlines each having a width of 0.018 (mm), extending in the horizontaldirection. Here, in these five straight lines, all of intervals betweentwo adjoining lines are 0.012 (mm) respectively. As the experimentalexample 4-5, FIG. 11( e) shows the polarizing-axis control plate areashading parts 183 constructed by the linear pattern where lines having awidth of 0.133 (mm) are arranged parallel to one another in thehorizontal direction at the pitch of 0.27 (mm), each line comprisingseven straight lines each having a width of 0.013 (mm), extending in thehorizontal direction. Here, in these seven straight lines, all ofintervals between two adjoining lines are 0.007 (mm) respectively.

In the 3D image display device 100 of the embodiment 1, FIG. 12 is adiagram showing the results of evaluating moiré and light transmissionrates about the comparative example shown in FIG. 8( a) and theexperimental examples shown in FIG. 11. Note that the evaluated valuesof moiré and the light transmission rates are similar to the evaluatedvalues of moiré and the light transmission rates shown in FIG. 10,respectively.

As shown in FIG. 12, as the sums of evaluated values of moiré in theexperimental examples 1-1, 3-2 and 3-3 represent small values of “4”,“7” and “8” respectively while the sum of evaluated values of moiré inthe comparative example is “10”, it can be said that these experimentalexamples have a constant effect of reducing the occurrence of moiré. Inaddition, since the light transmission rates in the experimentalexamples 1-1, 3-2 and 3-3 represent large values of “58”, “57” and “49”respectively in comparison with the light transmission rate of “45” (%)in the comparative example, the screens are increased in brightness incomparison with the comparative example. In this way, the smaller thediameter of a circle gets, the higher the value of synthetic judgment iselevated. Especially, it is more advantageous that the sum of evaluatedvalues of moiré is sufficiently lowered and the light transmission rateis sufficiently elevated so as to be sustainable for practical use inthe experimental example 1-1 adopting the arrangement of successivecircles each having a diameter less than 0.06 (mm), which is smallerthan either of the interval between the adjoining image generating areashading parts 163 and the interval between the adjoining interpixelshading parts 165.

Note that, while the evaluated values of oblique moiré in theexperimental examples 1-1, 3-2 and 3-3 are “2”, “3” and “4”respectively, the evaluated value of oblique moiré in the experimentalexample 2-5 represents a remarkably-small value of “1”. For the reason,it is considered that a single straight line having a width of 0.05 (mm)interferes the continuity of circles in the oblique direction to enhancethe optical random nature, so that the interference between the imagegenerating area shading parts 163 and the interpixel shading parts 165is reduced.

As mentioned above, since the polarizing-axis control plate area shadingpart 183 of the 3D image display device 100 of the embodiment 1 isformed so as to contain a plurality of circles each having a diametersmaller than either of the interval between the adjoining imagegenerating area shading parts 163 and the interval between the adjoininginterpixel shading parts 165, it is possible to improve the lighttransmission rate and reduce the occurrence of moiré.

Again, as shown in FIG. 12, since the sums of evaluated values of moiréin the experimental examples 1-3, 1-4, 4-3, 4-4 and 4-5 represent smallvalues of “8”, “3.5”, “4”, “3” and “2” respectively while the sum ofevaluated values of moiré in the comparative example is “10”, it can besaid that these experimental examples have a constant effect of reducingthe occurrence of moiré in common. In addition, since the lighttransmission rates in the experimental examples 1-3, 1-4, 4-3, 4-4 and4-5 represent large values of “56”, “57”, “52” and “47” respectively incomparison with the light transmission rate of “45” (%) in thecomparative example, the screens are commonly increased in brightness incomparison with the comparative example. In this way, the smaller thelinewidth of a straight line gets, the higher the value of syntheticjudgment is elevated. Especially, it is more advantageous that the sumsof evaluated values of moiré are sufficiently lowered and the lighttransmission rates are sufficiently elevated so as to be sustainable forpractical use in common with the experimental examples 1-3, 1-4, 4-3,4-4 and 4-5 where each linewidth is less than 0.04 (mm) as the linewidthof the adjoining image generating area shading part 163.

As mentioned above, since the polarizing-axis control plate area shadingpart 183 of the 3D image display device 100 of the embodiment 1 isformed so as to contain a plurality of straight lines each having alinewidth smaller than the linewidth of the image generating areashading part 163, it is possible to improve the light transmission rateand reduce the occurrence of moiré.

<<Additional Experiments for Evaluating Influence of Linear Pattern onMoiré Occurrence>>

Next, we carried out experiments for investigating the change of moiréand the change of light transmission rate by modifying thepolarizing-axis control plate area shading parts 183 to variousconfigurations, as shown below.

FIGS. 13( a) to (c) are views showing experimental examples of linearpatterns of the polarizing-axis control plate shading parts 183 in the3D image display device 100 of the embodiment 1.

As the experimental example 5-2, FIG. 13( a) shows the polarizing-axiscontrol plate area shading parts 183 constructed by the linear patternwhere respective lines each having a width of 0.135 (mm) are arrangedparallel to one another in the horizontal direction at the pitch of 0.27(mm), each line comprising successive graphic symbols arranged regularlyat the pitch of 0.05 (mm) in the horizontal direction, each graphicsymbols comprising a single line having a width of 0.05 (mm) and circlesarranged on both sides of the single line in the vertical direction andeach having a diameter of 0.035 (mm). As the experimental example 5-4,FIG. 13( b) shows the polarizing-axis control plate area shading parts183 constructed by the linear pattern where respective lines each havinga width of 0.130 (mm) are arranged parallel to one another in thehorizontal direction at the pitch of 0.27 (mm), each line comprisingsuccessive rectangular holes, 0.03 (mm) on a side each, arrangedregularly at the pitch of 0.06 (mm) in the horizontal direction. As theexperimental example 5-6, FIG. 13( c) shows the polarizing-axis controlplate area shading parts 183 constructed by the linear pattern whererespective lines each having a width of 0.140 (mm) are arranged parallelto one another in the horizontal direction at the pitch of 0.27 (mm),each line comprising successive rectangular holes arranged at random,0.035 (mm) on a side each. Here, the random arrangement means that therectangular holes are outlined on the black background, at the rate of25% per unit area.

In the 3D image display device 100 of the embodiment 1, FIG. 14 is adiagram showing the results of evaluating moiré and light transmissionrates about the comparative example shown in FIG. 8( a) and theexperimental examples shown in FIG. 13. Note that the evaluated valuesof moiré and the light transmission rates are similar to the evaluatedvalues of moiré and the light transmission rates shown in FIG. 10,respectively.

As shown in FIG. 14, as the sums of evaluated values of moiré in theexperimental examples 5-4 and 5-6 represent similar or larger values of“10” and “12” respectively while the sum of evaluated values of moiré inthe comparative example is “10”, it can be said that these experimentalexamples have no effect of reducing the occurrence of moiré. For thereason, it is considered that the boundaries between the polarizing-axiscontrol plate area shading parts 183 are in the form of straight lines.

On the other hand, the sum of evaluated values of moiré in theexperimental example 5-2 represents a remarkably-small value of “2.5”,allowing the occurrence of moiré to be further reduced in comparisonwith the experimental example 2-5. In addition, due to its smallness inthe diameter of each circle, the light transmission rate represents alarge value of “63”, so that the brightness of the screen is furtherincreased in comparison with the experimental example 2-5.

As mentioned above, since the polarizing-axis control plate area shadingpart 183 of the 3D image display device 100 of the embodiment 1 isformed so as to contain at least one straight line having a widthsmaller than either of the interval between the adjoining imagegenerating area shading parts 163 and the interval between the adjoininginterpixel shading parts 165 and a plurality of circles arranged alongthe straight line on the boundary's side and each formed with a diametersmaller than either of the interval between the adjoining imagegenerating area shading parts 163 and the interval between the adjoininginterpixel shading parts 165, the optical random nature is produced toreduce interferences with the image generating area shading parts 163and the interpixel shading parts 165. Thus, it is possible to improvethe light transmission rate and reduce the occurrence of moiré.

<<Additional Experiments for Evaluating Influence of Rectangle Positionon Moiré Occurrence>>

Next, we carried out experiments for investigating the change of moiréand the change of light transmission rate by changing the positions ofrectangles contained in the polarizing-axis control plate area shadingparts 183, as shown below.

FIGS. 15( a) to 15(e) are views showing experimental examples of thelinear patterns of the polarizing-axis control plate shading parts 183in the 3D image display device 100 of the embodiment 1.

As the experimental example 6-1, FIG. 15( a) shows the polarizing-axiscontrol plate area shading parts 183 constructed by the linear patternwhere respective lines each having a width of 0.135 (mm) are arrangedparallel to one another in the horizontal direction at the pitch of 0.27(mm), each line comprising successive rectangles arranged in respectivelines regularly in the vertical and horizontal directions, the rectanglebeing 0.1 (mm) on each horizontal side and 0.135 (mm) on each verticalside. Here, the interval between the adjoining rectangles is 0.05 (mm).As the experimental example 6-2, FIG. 15( b) shows the polarizing-axiscontrol plate area shading parts 183 constructed by the linear patternwhere respective lines each having a width of 0.135 (mm) are arrangedparallel to one another in the horizontal direction at the pitch of 0.27(mm), each rectangle in each line being shifted from avertically-adjoining rectangle by only 0.015 (mm) in the horizontaldirection, the rectangle being 0.1 (mm) on each horizontal side and0.135 (mm) on each vertical side. Here, the interval between theadjoining rectangles is 0.05 (mm). As the experimental example 6-3, FIG.15( c) shows the polarizing-axis control plate area shading parts 183constructed by the linear pattern where respective lines each having awidth of 0.135 (mm) are arranged parallel to one another in thehorizontal direction at the pitch of 0.27 (mm), each rectangle in eachline being shifted from a vertically-adjoining rectangle by only 0.03(mm) in the horizontal direction, the rectangle being 0.1 (mm) on eachhorizontal side and 0.135 (mm) on each vertical side. Here, the intervalbetween the adjoining rectangles is 0.05 (mm). As the experimentalexample 6-4, FIG. 15( d) shows the polarizing-axis control plate areashading parts 183 constructed by the linear pattern where respectivelines each having a width of 0.135 (mm) are arranged parallel to oneanother in the horizontal direction at the pitch of 0.27 (mm), eachrectangle in each line being shifted from a vertically-adjoiningrectangle by only 0.05 (mm) in the horizontal direction, the rectanglebeing 0.1 (mm) on each horizontal side and 0.135 (mm) on each verticalside. Here, the interval between the adjoining rectangles is 0.05 (mm).As the experimental example 6-5, FIG. 15( e) shows the polarizing-axiscontrol plate area shading parts 183 constructed by the linear patternwhere respective lines each having a width of 0.135 (mm) are arrangedparallel to one another in the horizontal direction at the pitch of 0.27(mm), each rectangle in each line being shifted from avertically-adjoining rectangle by only 0.075 (mm) in the horizontaldirection, the rectangle being 0.1 (mm) on each horizontal side and0.135 (mm) on each vertical side. Here, the interval between theadjoining rectangles is 0.05 (mm).

In the 3D image display device 100 of the embodiment 1, FIG. 16 is adiagram showing the results of evaluating moiré and light transmissionrates about the comparative example shown in FIG. 8( a) and theexperimental examples shown in FIG. 15. Note that the evaluated valuesof moiré and the light transmission rates are similar to the evaluatedvalues of moiré and the light transmission rates shown in FIG. 10,respectively.

As shown in FIG. 16, as the sums of evaluated values of moiré in theexperimental examples 6-1 and 6-2 represent the same values of “10” and“12” respectively while the sum of evaluated values of moiré in thecomparative example is “10”, it can be said that these experimentalexamples have no effect of reducing the occurrence of moiré.

On the other hand, as the sums of evaluated values of moiré in theexperimental examples 6-3, 6-4 and 6-5 represent small values of “8”,“4” and “4” in comparison with “10” in the sum of evaluated values ofmoiré in the comparative example, it can be said that these experimentalexamples have a constant effect of reducing the occurrence of moiré. Inaddition, since the light transmission rates in the experimentalexamples 6-3, 6-4 and 6-5 represent large values of “60”, “60” and “58”respectively in comparison with the light transmission rate of “45” (%)in the comparative example, the screens are increased in brightness incomparison with the comparative example.

In this way, the larger the shifting amount of each rectangle in thehorizontal direction gets, the higher the value of synthetic judgment iselevated. In the experimental examples 6-4 and 6-5 where each rectangleis shifted from the vertically-adjoined rectangle in the horizontallydirection by only ⅓ to ½ of the horizontal pitch of rectangles,especially, it is more advantageous that the sum of evaluated values ofmoiré is sufficiently lowered and the light transmission rate issufficiently elevated so as to be sustainable for practical use.

Note that there is concern that when the optical transmission rate getshigher, the crosstalk ratio is elevated.

Therefore, we performed experiments of investigating the linear patternsof the polarizing-axis control plate area shading parts 183 and thechanges of crosstalk ratio.

In the 3D image display device 100 of the embodiment 1, FIG. 17 is adiagram showing the results of crosstalk ratios with respect to eachview angle about the comparative example shown in FIG. 8( a), theexperimental example 1-1 shown in FIG. 8( b) and the experimentalexample 5-2 shown in FIG. 13( a).

As shown in FIG. 17, in the experimental examples 1-1 and 5-2 whoseoptical transmission ratios are respectively “58” (%) and “63” (%)against the comparative example having the optical transmission ratio of“45” (%), their crosstalk ratios represent similar values. Thus, it isconsidered that there is no deterioration in images by the geometricchange of the polarizing-axis control plate area shading parts 183.

As mentioned above, according to the 3D image display device of theembodiment 1, it is possible to improve the light transmission rate andreduce the occurrence of moiré.

In addition, as shown in FIG. 1, although the embodiment 1 has beendescribed while providing the illustration of both the right-eye imagegenerating areas 162 and the left-eye image generating areas 164 in theform of horizontally-segmentalized areas in the image generating unit160, they may be comprised of vertically-segmentalized areas in theimage generating unit 160, as shown in FIG. 18. Then, it is necessary tomodify the drive circuit for the image generating unit 160 and alsochange the compartmental direction between the first polarization areas181 and the second polarization areas 182 to a vertical direction.

Moreover, with the modification of the drive circuit for the imagegenerating unit 160, the right-eye image generating areas 162 and theleft-eye image generating areas 164 of the image generating unit 160 maybe formed in a lattice manner by compartmentalizing the unit 160vertically and horizontally, as shown in FIG. 19. In this case, thepolarizing-axis control plate 180 has to be formed in a lattice manner,corresponding to the image generating unit 160.

Again, although the embodiment 1 has been illustrated by an example ofthe 3D image display device 100 having a 24-inche screen, the screensize of the invention is not limited to only this size. For instance,also in the 3D image display device 100 having a 37-inch screen, it ispossible to improve the optical transmission ratio and reduce theoccurrence of moiré similarly.

<Embodiment 2 >

In the embodiment 1, the invention has been described by an example ofthe 3D image display device 100 where when right-eye image light andleft-eye image light enter the first polarization areas 181 and thesecond polarization areas 182 respectively, the polarizing-axis controlplate 180 emits the incident right-eye image light and the incidentleft-eye image light in the form of linearly-polarized lights havingpolarizing axes at right angles to each other. However, the presentinvention is not limited to only this device.

The embodiment 2 will be described by an example of a 3D image displaydevice 101 where when right-eye image light and left-eye image lightenter the first polarization areas 181 and the second polarization areas182 respectively, a polarizing-axis control plate emits the incidentright-eye image light and the incident left-eye image light in the formof circularly-polarized lights whose polarizing axes are rotated inopposite directions to each other.

FIG. 21 is an exploded perspective view of the 3D image display device101 of the embodiment 2.

In the 3D image display device 101 shown in FIG. 21, elements identicalto those of the 3D image display device 100 shown in FIG. 1 areindicated with the same reference numerals, respectively and theirdescriptions are eliminated.

As shown in FIG. 21, the 3D image display device 101 includes apolarizing-axis control plate 185 in place of the polarizing-axiscontrol plate 180 of the 3D image display device 100. Thispolarizing-axis control plate 185 includes a substrate 184 and firstpolarization areas 186 and second polarization areas 187 both formed onthe substrate 185. In this polarizing-axis control plate 185, theposition and size of the first polarization areas 186 and the secondpolarization areas 187 correspond to the position and size of theright-eye image generating areas 162 and the left-eye image generatingareas 164 of the image generation part 160 respectively, as similar tothe position and size of the first polarization areas 181 and the secondpolarization areas 182 of the above polarizing-axis control plate 180.Therefore, in the usage state of the 3D image display device 101, theright-eye image light penetrating through the right-eye image generatingareas 162 enters the first polarization areas 186, while the left-eyeimage light penetrating through the left-eye image generating areas 164enters the second polarization areas 187.

The first polarization area 186 emits the incident right-eye image lightin the form of right-handed circularly-polarized light. While, thesecond polarization areas 187 emits the incident left-eye image light inthe form of left-handed circularly-polarized light. Note that, in FIG.21, arrows Y5, Y6 of the polarizing-axis control plate 185 designaterespective rotating directions of the polarized lights penetratingthrough this polarizing-axis control plate 185. For the firstpolarization areas 186, there are used, for example, quarter wavelengthplates having optical axes extending in the horizontal direction. Forthe second polarization areas 187, there are used, for example, quarterwavelength plates having optical axes extending in the verticaldirection. In the polarizing-axis control plate 185, the firstpolarization area 186 and the second polarization area 187 arerespectively divided into a plurality of tiny cells in the horizontaldirection, similarly to the first polarization area 181 and the secondpolarization area 187 of the above polarizing-axis control plate 180.

When viewing the 3D image display device 101 equipped with thepolarizing-axis control plate 185, the observer 500 puts on polarizingglasses having quarter wavelength plates and polarizing lenses arrangedin respective positions corresponding to the right eye 512 and the lefteye 514 respectively. In the polarizing glasses, the quarter wavelengthplate arranged in the position corresponding to the right eye 512 of theobserver 500 has an optical axis extending in horizontal direction,while the quarter wavelength plate arranged in the positioncorresponding to the left eye 514 of the observer 500 has an opticalaxis extending in vertical direction.

In addition, the polarizing lens arranged in the position correspondingto the right eye 512 of the observer 500 and the polarizing lensarranged in the position corresponding to the left eye 514 of theobserver 500 have their transmission axes extending 45-degrees obliqueright together when viewed from the observer 500 and their absorptionaxes intersecting with the transmission axes at right angles. Further,the polarizing axis of the polarizing lens arranged in the positioncorresponding to the right eye 512 is perpendicular to the polarizingaxis of the polarizing lens arranged in the position corresponding tothe right eye 514.

Under the condition that the observer 500 observes the 3D image displaydevice 101 with the above polarizing glasses, when circularly-polarizedlight whose polarizing axis is rotated right-handed in a view from theobserver 500 enters the polarizing glass corresponding to the right eye512 of the observer 500, the circularly-polarized light is converted tolinearly-polarized light of 45-degrees oblique right by the abovequarter wavelength plate having its optical axis extending in thehorizontal direction and thereafter, the resultant polarized lightpenetrates through the above polarizing lens into the right eye 512 ofthe observer 500.

Further, when circularly-polarized light whose polarizing axis isrotated left-handed in a view from the observer 500 enters thepolarizing glass corresponding to the left eye 514 of the observer 500,the circularly-polarized light is converted to linearly-polarized lightof 45-degrees oblique right by the above quarter wavelength plate havingits optical axis extending in the vertical direction and thereafter, theresultant polarized light penetrates through the above polarizing lensinto the left eye 514 of the observer 500.

In this way, by observing the 3D image display device 100 with the abovepolarizing glasses, the observer can observe only a right-eye imagecontained in the right-eye image light left by the observer's right eye512 and observe only a left-eye image contained in the left-eye imagelight left by the observer's left eye 514. Thus, the observer 500 canrecognize these right-eye image and left-eye image in the form of astereoscopic image.

According to the 3D image display device 101 of the embodiment 2 as wellas the 3D image display device 100 of the embodiment 1, since itincludes the first polarization areas 181, the second polarization areas182 and the polarizing-axis control plate area shading parts 183 eacharranged at the boundary between the first polarization area 181 and thesecond polarization area 182, respective areas of different opticaltransmission ratios appear at random, so that moiré between the imagegenerating area shading parts 163 and the interpixel shading parts 165is reduced in contrast between moirés' black portions and whiteportions, allowing the occurrence of moiré to be reduced.

<Embodiment 3>

Although the 3D image display device 100 of the embodiment 1 isconstructed so that the first polarization area 181 and the secondpolarization area 182 of the polarizing-axis control plate 180 coincidewith the right-eye image generating area 162 and the left-eye imagegenerating area 164 of the image generation part 160 in terms of theirpositions and sizes, the invention is not limited to only thisarrangement.

The embodiment 3 will be described by an example of a 3D image displaydevice 102 where the polarizing-axis control plate 180 is arranged sothat the positions and sizes of the first polarization area 181 and thesecond polarization areas 182 correspond to the positions and sizes ofthe right-eye image generating area 162 and the left-eye imagegenerating area 164 of the image generation part 160, depending on adistance from the device up to the position of an observer.

FIG. 22 is a constitutional view showing the constitution of the 3Dimage display device 102 of the embodiment 3. Note that, in the 3D imagedisplay device 102 shown in of the embodiment 3, elements identical tothose of the 3D image display device 100 of FIG. 1 are indicated withthe same reference numerals respectively, and their descriptions areeliminated in what follows.

As shown in FIG. 22, the 3D image display device 102 includes apolarizing-axis control plate 190 in place of the polarizing-axiscontrol plate 180 of the 3D image display device 100.

The polarizing-axis control plate 190 includes the substrate 184 (notshown), first polarization areas 191 and second polarization areas 192both formed on the substrate 185 (both not shown) and polarizing-axiscontrol plate area shading parts 193 each arranged at the boundarybetween the first polarization area 191 and the second polarization area192.

Here, the polarizing-axis control plate area shading part 193 has thesame constitution as the polarizing-axis control plate area shading part183 included in the 3D image display device 100 of the embodiment 1.

In the polarizing-axis control plate 190, based on a distance from anobserver's position P envisaged from the screen size of the 3D imagedisplay device 100 up to the image generating unit 160 and a distancefrom the observer's position P up to the polarizing-axis control plate190, the first polarization areas 191, the second polarization areas 192and the polarizing-axis control plate area shading parts 193 of thepolarizing-axis control plate 190 are arranged so that the imagegenerating area shading parts 163 and the polarizing-axis control platearea shading parts 193 overlap each other in a view from the observer.

In this way, according to the 3D image display device 102 of theembodiment 3, when the observer performs an observation at the positionP, the image generating area shading parts and the polarizing-axiscontrol plate area shading parts appear to overlap each other. However,if the observer performs the observation in a position closer to orfurther from the 3D image display device 102 than the position P, theimage generating area shading parts and the polarizing-axis controlplate area shading parts will appear to be shifted from each other.

According to the 3D image display device 102 of the embodiment 3, itincludes the first polarization areas 181, the second polarization areas182 and the polarizing-axis control plate area shading parts 183 eacharranged at the boundary between the first polarization area 181 and thesecond polarization area 182, as similar to the 3D image display device100 of the embodiment 1. Thus, even when such an observer observes it ina position other than the position P, respective areas of differentoptical transmission ratios appear at random, so that moiré between theimage generating area shading parts 163 and the interpixel shading parts165 is reduced in contrast between moirés' black portions and whiteportions, allowing the occurrence of moiré to be reduced.

Note that, without being limited to the above-mentioned printingtechnique, the polarizing-axis control plate area shading parts 183, 193may be formed by a variety of techniques, such as photolithographymethod.

In the meantime, as for the multifraction forming of the linear patternof the polarizing-axis control plate area shading part 183 with use ofthe above-mentioned printing technique, if the multifractionatedprofiles approach each other or the viscosity of ink in use is low,there is a possibility that the approaching profiles are connected toeach other. For instance, there may be a case of connection betweenlines situated next to each other, between dots (rectangular, circular,elliptical, polygonal) lying next to each other or between a line and adot (rectangular, circular, elliptical, polygonal) lying next to eachother.

FIGS. 23 illustrate one example of ink flow when adopting thesegmentation pattern of the experimental example 1-1. FIG. 23(A) is anenlarged view of dots of FIG. 8( b), showing the design status. FIG.23(B) is an enlarged view of dots formed under the condition of FIG.23(A) actually.

As shown in FIG. 23(B), in case of printing with the use of the linearpattern of the experimental example 1-1 shown in FIG. 23(A), the dotsare connected with each other, so that spaces centrally located in a dotrow are occupied by ink.

When the adjoining profiles are connected to each other in this way, thepolarizing-axis control plate area shading part 183 is not printeduniformly since the connected part resulting from the ink flow has afilm thickness smaller than that of a dot part. Accordingly, the opticalrandom nature of transmissive light is maintained to bring about asimilar effect.

INDUSTRIAL APPLICABILITY

As mentioned above, according to the present invention, it is possibleto reduce the occurrence of moiré.

REFERENCE SIGNS LIST

100, 101, 201 3D Image Display Device

120 Light Source

130 Image Display Unit

150 Polarizing Plate

160 Image Generating Unit

162 Right-eye Image Generating Area

163 Image Generating Area Shading Part

164 Left-eye Image Generating Area

170 Polarizing Plate

180, 185, 190 Polarizing-axis Control Plate

181, 186, 191 First Polarization Area

182, 187, 192 Second Polarization Area

183, 193 Polarizing-axis Control Plate Area Shading Part

200 Polarizing Glasses

What is claimed is:
 1. A 3D image display optical member comprising: animage generating unit having a first modulated-light generating area tooptically modulate linearly-polarized light having a first polarizingaxis with a predetermined angle based on a first image signal therebygenerating first modulation-polarization light for emission and a secondmodulated-light generating area to optically modulate thelinearly-polarized light having the first polarizing axis based on asecond image signal thereby generating second modulation-polarizationlight for emission; a polarizing plate configured to transmit and emit,of the first modulation-polarization light and the secondmodulation-polarization light emitted from the image generating unit,the first modulation-polarization light and the secondmodulation-polarization light as linearly-polarized light having asecond polarizing axis different from the first polarizing axis; and apolarizing-axis control plate having a first polarization area arrangedcorresponding to the position of the first modulated-light generatingarea in the image generating unit to polarize a polarizing axis of thefirst modulation-polarization light, which has been emitted from thepolarizing plate and entered the first polarization area, to a thirdpolarizing axis thereby generating a third modulation-polarization lightfor emission, a second polarization area arranged corresponding to theposition of the second modulated-light generating area in the imagegenerating unit to polarize a polarizing axis of the secondmodulation-polarization light, which has been emitted from thepolarizing plate and entered the second polarization area, to a fourthpolarizing axis thereby generating a fourth modulation-polarizationlight for emission, and a shading part arranged at a boundary betweenthe first polarization area and the second polarization area to shadeincident light, wherein the image generating unit has an imagegenerating area shading part arranged at a boundary between the firstmodulated-light generating area and the second modulated-lightgenerating area to shade incident light, and the shading part is formedso as to contain a plurality of straight lines each having a widthsmaller than a linewidth of the image generating area shading part.
 2. A3D image display device comprising: a light source; a linearly-polarizedlight generating unit configured to transmit, of light emitted from thelight source, first linearly-polarized light having the first polarizingaxis; and a 3D image display optical member of claim 1, wherein an imagegenerated by the third modulation-polarization light emitted from thefirst polarization area of the polarizing-axis control plate isestablished as a right-eye image, while an image generated by the fourthmodulation-polarization light emitted from the second polarization areais established as a left-eye image.
 3. A 3D image display optical membercomprising: an image generating unit having first modulated-lightgenerating areas to optically modulate linearly-polarized light having afirst polarizing axis with a predetermined angle based on a first imagesignal thereby generating first modulation-polarization light foremission and second modulated-light generating areas to opticallymodulate the linearly-polarized light having the first polarizing axisbased on a second image signal thereby generating secondmodulation-polarization light for emission; a polarizing plateconfigured to transmit and emit, of the first modulation-polarizationlight and the second modulation-polarization light emitted from theimage generating unit, the first modulation-polarization light and thesecond modulation-polarization light as linearly-polarized light havinga second polarizing axis different from the first polarizing axis; and apolarizing-axis control plate having first polarization areas arrangedcorresponding to the positions of the first modulated-light generatingareas in the image generating unit to polarize a polarizing axis of thefirst modulation-polarization light, which has been emitted from thepolarizing plate and entered the first polarization areas, to a thirdpolarizing axis thereby generating a third modulation-polarization lightfor emission, second polarization areas arranged corresponding to theposition of the second modulated-light generating area in the imagegenerating unit to polarize a polarizing axis of the secondmodulation-polarization light, which has been emitted from thepolarizing plate and entered the second polarization areas, to a fourthpolarizing axis thereby generating a fourth modulation-polarizationlight for emission, and shading parts each arranged at a boundarybetween the first polarization area and the second polarization area toshade incident light, wherein the image generating unit has imagegenerating area shading parts each arranged at a boundary between thefirst modulated-light generating area and the second modulated-lightgenerating area to shade incident light and interpixel shading partseach arranged at a boundary between pixels provided in each of the firstmodulated-light generating areas and the second modulated-lightgenerating areas to shade incident light, the shading part is formed soas to contain at least one straight line having a width smaller than aninterval between the adjoining image generating area shading parts or aninterval between the adjoining interpixel shading parts and a pluralityof circles arranged on the side of the boundary along the straight line,the circles each having a diameter smaller than either the intervalbetween the adjoining image generating area shading parts or theinterval between the adjoining interpixel shading parts.
 4. A 3D imagedisplay optical member comprising: an image generating unit having firstmodulated-light generating areas to optically modulatelinearly-polarized light having a first polarizing axis with apredetermined angle based on a first image signal thereby generatingfirst modulation-polarization light for emission and secondmodulated-light generating areas to optically modulate thelinearly-polarized light having the first polarizing axis based on asecond image signal thereby generating second modulation-polarizationlight for emission; a polarizing plate configured to transmit and emit,of the first modulation-polarization light and the secondmodulation-polarization light emitted from the image generating unit,the first modulation-polarization light and the secondmodulation-polarization light as linearly-polarized light having asecond polarizing axis different from the first polarizing axis; and apolarizing-axis control plate having first polarization areas arrangedcorresponding to the positions of the first modulated-light generatingareas in the image generating unit to polarize a polarizing axis of thefirst modulation-polarization light, which has been emitted from thepolarizing plate and entered the first polarization areas, to a thirdpolarizing axis thereby generating a third modulation-polarization lightfor emission, second polarization areas arranged corresponding to theposition of the second modulated-light generating area in the imagegenerating unit to polarize a polarizing axis of the secondmodulation-polarization light, which has been emitted from thepolarizing plate and entered the second polarization areas, to a fourthpolarizing axis thereby generating a fourth modulation-polarizationlight for emission, and shading parts each arranged at a boundarybetween the first polarization area and the second polarization area toshade incident light, wherein the image generating unit has imagegenerating area shading parts each arranged at a boundary between thefirst modulated-light generating area and the second modulated-lightgenerating area to shade incident light and interpixel shading partseach arranged at a boundary between pixels provided in each of the firstmodulated-light generating areas and the second modulated-lightgenerating areas to shade incident light, the shading part is formed soas to contain a plurality of circles each having a diameter smaller thanan interval between the adjoining image generating area shading parts oran interval between the adjoining interpixel shading parts.
 5. A 3Dimage display optical member comprising: an image generating unit havingfirst modulated-light generating areas to optically modulatelinearly-polarized light having a first polarizing axis with apredetermined angle based on a first image signal thereby generatingfirst modulation-polarization light for emission and secondmodulated-light generating areas to optically modulate thelinearly-polarized light having the first polarizing axis based on asecond image signal thereby generating second modulation-polarizationlight for emission; a polarizing plate configured to transmit and emit,of the first modulation-polarization light and the secondmodulation-polarization light emitted from the image generating unit,the first modulation-polarization light and the secondmodulation-polarization light as linearly-polarized light having asecond polarizing axis different from the first polarizing axis; and apolarizing-axis control plate having first polarization areas arrangedcorresponding to the positions of the first modulated-light generatingareas in the image generating unit to polarize a polarizing axis of thefirst modulation-polarization light, which has been emitted from thepolarizing plate and entered the first polarization areas, to a thirdpolarizing axis thereby generating a third modulation-polarization lightfor emission, second polarization areas arranged corresponding to thepositions of the second modulated-light generating areas in the imagegenerating unit to polarize a polarizing axis of the secondmodulation-polarization light, which has been emitted from thepolarizing plate and entered the second polarization areas, to a fourthpolarizing axis thereby generating a fourth modulation-polarizationlight for emission, and shading parts each arranged at a boundarybetween the first polarization area and the second polarization area toshade incident light, wherein the image generating unit has imagegenerating area shading parts each arranged at a boundary between thefirst modulated-light generating area and the second modulated-lightgenerating area to shade incident light and interpixel shading partseach arranged at a boundary between pixels provided in each of the firstmodulated-light generating areas and the second modulated-lightgenerating areas to shade incident light, the shading part includes aplurality of rectangles arranged along the boundary between the firstpolarization area and the second polarization area and also arranged soas to be shifted from rectangles in the shading part provided at theadjoining boundary, in the arranging direction of the rectangles by only⅓ to ½ of a horizontal pitch at which the rectangles provided at theadjoining boundary are arranged.